Devices of the above-mentioned type are advantageously used for a gentle and noncontact positioning or moving of sensitive goods, such as paper webs or glass plates, records and CDs, but also silicon plates for semiconductors and the like.
Therefore, the passages provided in the support surface and as a rule, in flow connection with a compressed air source, are nozzles which compress the air underneath the piece good, the latter being then kept in suspension by the air.
Thereby, particularly where large surfaces are concerned, a large number of nozzles is required, leading to a high cost of the installation and a high consumption of flow medium.
Besides, if such systems are used in a so-called clean room, wherein from the ceiling a weak, downwardly directed air stream is constantly maintained in order to keep down the dust and the like, counterproductive air turbulence can occur, due to the punctiform exit of the air from the nozzle.